Description: Schizophrenia is not a single disease, but a broad category of mental illnesses involving some form of psychosis (being out of touch with reality).

Symptoms: Symptoms include low sociability, cognitive impairment (also called thought disorder), psychotic episodes including hallucinations and delusions. Mental and social functioning decline for a number of years and memory is often impaired. In up to a third of patients, the disease progresses from the first episode onward; in others, it fluctuates between psychotic flare-ups and remissions.

Number of Americans diagnosed: Schizophrenia affects more than 2.7 million people in America.

Long-term problems/treatments: Schizophrenia often starts out very slowly and progresses to a severely disabling mental illness, generally treated with antipsychotic medications. The consequences for work and relationships are usually severe and difficult to repair, even if symptoms improve. Schizophrenia has a devastating effect on all aspects of human thought, emotion and expression.